Valve stem



J. CROWLEY VALVE STEM April 20, 1937.

Filed` April 1'7, 1954 Patented Apr. 20, 1937 UNITED STATES PATENToFFicE VALVE STEM Application April 17, 1934, Serial No. 720,992

2 Claims.

This invention relates to a valve stern such as is used on pneumatictires.

It has been customary to provide metal valve stems for pneumatic tireswith heads at the in- 5 ner end of the stems and located within ,thetire tubes, while the stems extend outwardly through openings in thetubes. In order to strengthen the tire tubes at the point of attachmentof the stems, reenforcing patches usually are vulcanized to the tubes atsuch points. The stems are held in position in the tire tubes by meansof spreader plates arranged on the stems and en gaging the outside ofthe tubes, nuts screwed down on the externally threaded stems serving toclamp the tubes between the heads and the spreader plates.

This form of valve stem construction is open to the objection that themechanical connection between the stem and tire tube does not form aneicient air-tight seal and leaks frequently occur at the point ofconnection. Also, the mechanical connection requires the useof a numberof separate parts such as the spreader plate, clamping nut, and otherparts.

An object of the invention is to provide a valve stem, either metal orrubber, which is integrally united to the tire tube by being vulcanizedthereto, thus obviating the likelihood of leaks at the point ofconnection and the use of a number of separate parts.

In the use of rubber valve'stems or valve stems partially constructed ofrubber, the opening for the stem in the tire rim becomes sealed by therubber of the stem packing into and around -the opening, with the resultthat when the tire tube is inflated the air between the tube and thetire casing and rim cannot escape through the opening and will betrapped between the tube and tire rim and casing.

Another objectof the invention is to provide a valve stem constructionapplicable to stems constructed entirely or partially of rubber and ofsuch character that the rim opening will not be sealed air-tight by thestem and the air be- 45 tween the tube and the tire casing and rim willbe free to escape as the tube `is inflated.

, Another object of the invention is to provide a valve stemconstruction such that the stem` therethrough. Also, the type of valvestem just referred to has the disadvantage that the edge ofthe rim atthe opening cuts into the rubber of the stem and seriouslyv damages thesame and, infact, often renders the stem useless.

A further object of the present invention is to provide a valve stemconstruction such that it will be substantially unnecessary to ille therim opening when inserting the stem therethrough and also such that theedge of the rim at the opening will not injure or cut the stem proper.Further and additional objects and advantages will become apparenthereinafter during the detailed description which is to follow of twoembodiments of the invention that are .illustratedin the accompanyingdrawing, wherein Figure 1 is a fragmentary sectional view through a tirecasing, tube and rim and shows the base of the valve stem embodying oneform of the invention in section, while the stern itself is shown inelevation.

Fig. 2 is an enlarged View of the form shown in Fig. 1, the rim andcasing being omitted.

Fig. 3 is a sectional view taken substantially on line 3--3 of Fig. 2,looking in the direction of the arrows. l

Fig. 4 is an enlarged sectional view through a different form of theinvention from that shown in Figs. 1 3, inclusive, and

Fig. 5 is a sectional view taken substantially on line 5-5 of Fig. 4,looking inthe direction of the arrows.

In Fig. 1 the valve stem is illustrated as carried by a tire tube I0arranged in a casing II, which stein extends outwardly through theopening I2 in the rim I3 and toward the outer sideof the wheel whichcarries the rim.

The valve stem comprises abase Il formed of rubber and somewhat conicallin shape in that it is of increasing thickness toward its center. Thebase I4 is vulcanized to thetube I0 and in eifect becomes an :integralpart thereof and actually .serves as a reenforcement forthe tube at thepoint where the stem is attached thereto.

A stem I5 formed of suitable metal and having a bore I6 extendingtherethrough and of such shape as to receive therein the usual valveinsides is secured to the base as will later be explained. 'Ihe bore"I6, as is customary, is threaded 'within a reduced nipple II at theouter end of the stem to receive the threaded plug of a valve insides,while the stem and the reduced' nipple are externally threaded so thatsuitable dust or valve caps can be mounted thereon, as

desired.

toward the stem, while its upper' side extends substantiallyperpendicular to the stem and forms with -the projection I8 an, annulargroove 20 therebetween. Below the projection I9 the stem is furtherprovided with another annular and lateral projection 2| that extendsoutwardly beyond the circumference of the projection I8, the

upper surface of the projection 2| being outwardly and downwardlyinclined, as viewed in the drawing. At the extreme inner end of the stemthere is still another annular and lateral projection 22 that extendsvoutwardly a shorter distance than either of the projections I8 and 2|.The lower side of the projection 2| and the upper side of theprojection22 define an. annular groove therebetween.

. The rubber base I4 is mounted on the lower end of the stem with itsinner surface flush 'with the upper side of the projection 22 and withportions of the base extending into the groove 20 between theprojections I8 and I9, into the groove between the projections I9 and 2|and into the groove between the projections 2| and 22. It will be notedthat the manner in which the base extends into the grooves between theprojections of the stem and the manner in which the projections extendinto thebase provide a secure interlock between the stem and base,whereby the base and stern may be securely vulcanized together.

An upwardly and inwardly tapered metal ring 23 is mounted on the sternand base and has at its upper end an inturned annular iiange 24 theinner and lower edge of which bears upon the upper downwardly inclinedside of the projection I8 and has at itslower end an outwardly extendingannular ange 25 which is countersunk into the base '|4, it being notedthat the outer edge of the projection I8 engages the' inner side of thering between the anges 24 and- 25.

The rubber base is vulcanized to the stem and ring and the structure ineffect becomes one integral device. It will beV noted that the ring 23by extending outwardly and downwardly allows a substantial portion ofthe base I4 to be received and locked between it and the stem, thusfurther increasing the security of the connection between the stem andbase.

The stem and base are positioned upon and vulcanized to the tube I0 withthe projection 22 of the stem located inan opening in the tube,

the inner surface of the 'tube being illustrated as substantiallyilushwith the inner surface of the projection 22. When the stem and base arevulcanized to the tube it becomes in eiect an integral part of the tubeand there is no possibilityof an air leak occurring at the point ofconnection of the stem with the tube, while the rela-v tively thick baseI4 of the' stem acts as a reenforcement for the tube at this point,which fact is of considerable importance inasmuch as tire tubes aresubjected to the greatest strains at the points where the valve stemsare connected thereto.

When the tube with the stem thereon `is arranged in the casing II andmounted on the rim I3 the stem will extend through the rim opening I2.When the tube is inated the base I4 will extend into and substantiallyfillthe recessed portion I3a of the rim beneath the rim opening l2.while the ring 23 will lie in the opening and center the valve stem, itbeing noted that the tapered or conical formation of the ringcompensates for variations in the size of the rim opening. Irlasmuch asthe ring 23 and its ange 25 provides a metal to metal contact between itand the rim I3, the opening I2 will not be sealed air-tight as is thecase when a rubber stem extendstherethrough and such air as is trappedbetween the tube I0 and the casing II and rim I3 when the tube is inatedmay readily escape. Also since the ring 23 is tapered the stem,in casethe tube is punctured and becomes deated, may swing suiciently to permitit to be pulled through the opening, thus obviating likelihood of thestem being pulled out of the tube.

Although thering 23 permits the escape of air trapped between the rim,casing and tire tube and also provides for suiiiient lateral movement ofthe stem in case of deation of the tube to.

allow it to pull through the opening it will readily be seen that thering 23 forms a sufcient seal against the entrance of dirt and otherforeign matter through the opening I2.

Another important feature of the construction just described, asreference to Figs.. l and 2 will indicate, is that the inner side of thering 23 engagesthe projection I8, while the ange -25 engages the innerside of the tire rim adjacent the opening I2.` It will be seen that thering 23 takes all the thrust placed on the base of the stem by the airpressure in the tire and prevents the rubber of the base between thestem and the ring from being compressed after the tire is inflated.

In the form of the invention shown in Figs. 4 and 5 the valve stem isillustrated as a rubber stem provided with a metal insert which receivesthe valve insides and can have screwed thereon the valve or dust cap.

The base 26 of the stem is similar to the base I4 in the previouslydescribed form in that it increases in thickness towards its centralpoint and is vulcanized to the tube I0. -The base 26 at its tendingconical portion 21 from which extends a cylindrical portion 28. The baseand' the portions 21 and 28 are integrally formed of rubber and there isin the portions 21 and 28 a bore into which extends the metal insert 29,while a re.-

' duced'bore 3D extends through the base and into the portion 21 andcommunicates With the open ing 3| in the tire tube and the lower end ofthe bore 32 in the metal insert 29 which receives theA 'a valve cap maybe screwed.

A conical metal ring 36 ts upon the conical portion 21 of the rubberstem and has at its lower end an outturned annular ange 31 that bearsupon the base 26 at the lower end of the conical portion 21. Therubberstem is vulcanized to the ring 36, as well as to the insert 29, and theconvStrution after such vulcanization becomes in ef- 'center point isprovided with an upwardly exfect an integral device that can be appliedand vulcanized to the tire tube I so as to be integrally connected tothe tube.

In the form of the invention just described the ring 36 serves the samefunctions as does the ring 23 in thefirst described form in that itcenters the stem in the rim opening, provides a metal to metal contactbetween the stern and the edge of the rim opening thus obviating dangerof sealing the rim opening whereby the air between the tube, casing andrim may escape when the tube is inflated and also permits of suicientlateral movement of the stem when the tube isv deflated to allow thestem to pull through the rim opening.

l5 In addition to these functions the ring 36 prevents the edge of therim opening from;cutting into and wearing the rubber stern as nowhappens with the rubber stems in use at the present time.

The ring 36 further serves to reenforce the rubber stern and hold thesame against bulging outwardly when the tube is inflated. The ordinary lrubber stem possesses the disadvantage' that under the pressure of theair in the tube there is a tendency for the stem to bulge outwardlyadjacent the rim opening, thus further increasing the likelihood of thestem being cut and injured by the rim and also aggravating'the sealingaction of the stem in the rim opening. As above stated, the presentinvention eliminates these disadvantages.

Although two preferred embodiments of the invention have beenillustrated and described.

herein, it will be understood that the invention is susceptibleofvarious modifications and adaptations within the scope of the appendedclaims.

Having thus described my invention, I claim:

1.` A valve stem comprising a rubber base adapted to be vulcanized to atire tube, a metal stem secured to said base and adapted to extendthrough the usual rim opening, said stem having a laterally projectingportion, and a conical rigid ring secured to said stem and base andengaging said projecting portion of the stem, said ring having a flangeengaging said base and adapted to contact with the inner side of the rimwhereby any thrust placed on the base by the air pressure will be takenby the ring. v

2. A valve stem comprising a rubber base, a metal stem secured to thebase and having laterally extending portions one of which is above the-base and another of which is embedded in the base, and a rigid4 conicalring arranged on said stem and base having its small end inturned andengaging the rst mentioned laterally exsaid ring confining `a portion ofsaid base between it and a part of the stem.

J OHN C. CROWLEY.

